1. Field of the Invention
This invention relates to a unique rotary travelling device in which a supporting member travels along a travelling surface while rotating around an axis substantially perpendicular to the travelling surface. This rotary travelling device is suitable for carrying out a treatment such as grinding or cleaning on a travelling surface.
2. Description of the Prior Art
In the construction of dams, for example, concrete is placed repeatedly a number of times until the desired height is attained. The thickness of concrete placed each time is about 30 cm. Hence, in order to construct a dam having a height of 100 meters, concrete should be placed repeatedly more than 300 times. In such dam construction, the surface of the placed concrete should be ground (this grinding is generally called "green cut") before the next concrete is placed. Otherwise, the placed concrete and the next concrete are not bonded as required. The surface of the placed concrete is ground by a surface grinding device having a rotating disc provided with a wire brush at its under surface.
The conventional surface grinding device does not have a self-travelling function, and the operator should properly move the surface grinding device along the surface of the concrete to be ground. Since the rotating disc having a wire brush in contact with the concrete surface is rotated, the movement of the surface grinding device by the operator is not easy and is unstable. Accordingly, the grinding of the concrete surface in the past is a complex operation requiring much labor. Furthermore, it is extremely difficult, if not impossible, to ground the entire concrete surface uniformly.